16Introduction4. GPSGlobal Positioning System (GPS): a system developed and operated by the United StatesGovernment that pinpoints your present location by utilizing latitudinal and longitudinal datareceived from at least 4 satellites (sometimes only 3 are used).Situations when GPS signal reception isimpossibleThe following are situations when the GPSsignal cannot be received.• When the GPS signal is obstructed whiledriving through building clusters, tunnels oroverpasses• When the signal is obstructed by an objectplaced on or near the GPS antenna• When the GPS satellite is not sending anysignals to the earth (signal emission may behalted due to modifications or repairsconducted by the U.S. Tracking Control Center, the organization responsible for controllingGPS signals)• When a digitally formatted cellular telephone unit is brought near the GPS antennaScreen with GPS signal reception in progressHandling the GPS antenna• Consult a specialist at the store of purchase for how to install the GPS antenna.• Do not apply paint or wax onto the GPS antenna. Otherwise, signal receptionsensitivity may be diminished or signal reception may be rendered impossible.• Do not pull on the cord when uninstalling or moving the GPS antenna.Otherwise, short circuits or disconnections may result.• See page 136 for information concerning GPS signal accuracy and errors. Seepage 155 for definitions of the terminology employed.
